Length 21-35 mm. C. sycophanta is characterized by a strongly transverse pronotum, sinuate behind. The lateral margin of the pronotum is thick, conspicuously elevated, and it disappears just before of the basal angles. Head and pronotum are wrinkled and sparsely punctured. The sculpture of elytra is flattened with smooth intervals and with clearly visible punctures on the striae. The tarsi of the male forelegs have hairy pads under the sole of the first three dilated segments. C. sycophanta is found, and in some years is quite common, in northern Africa and throughout Europe (including the Mediterranean Islands).
Towards north, C. sycophanta has been found sporadically in Denmark. In Sweden it is also very rare and it has been captured in single specimens only in the south of the county (Lindroth, 1985: 47), but some remains of this species were found in lacustrine sediment (gyttja) deposited on the shore of the ancient lake Bare, near Halmstad and dated by pollen analysis to a warmer period around 10,000 years BC (Welinder, 1970). Recently it has been accidentally imported in Finland, with vegetable foods (Bistrom, 1983: 212). In Norway, any recent captures of C. sycophanta are not known and in any way they seem improbable, however a single specimen found in 1921 should still be preserved in the entomological collections of the University of Bergen (www.gbif.org/).
To the east, C. sycophanta spreads to Asia Minor, Iran, central Asia (Azerbaijan, Turkmenistan and Kyrgyzstan) up to western Siberia. It is indicated by various authors (Yu, 1982; Deuve, 1997) of Xinjiang in northern China, based on an ancient citation of Breuning, (1927: 174), which literally reads: “ Turkestan, towards East up to the Thian Shan”. C. sycophanta is not rarely found on the south-eastern coast of England but it is possibly an occasional immigrant. It has been imported into the eastern United States in 1905-1910 (Burgess 1911, Burgess & Collins 1917). Its range has continued to expand at a rate of dispersion, calculated at 6 km/year and now extends from southern Maine and all New England states south into Pennsylvania, Delaware, Maryland, and West Virginia (Schaefer & al. 1999). C. sycophanta was unsuccessfully introduced in Canada, in New Brunswich and in Vancouver island (Lindroth, 1961: 46), however, it seems to be present in Nova Scotia (Erwin, 2007: 105).Normally the upper body of C sycophanta is two-tone with bluish head and pronotum, and with coppery or golden green elytra. However the color is variable, in some cases also because affected by climatic conditions under which the pupation took effect. It is possible to find specimens with cupric elytra and dark bluish pronotum or, very rarely, it is possible to find uniformly colored specimens, green blue (prasinum Lapouge) or light blue (azureum Letzner). In some localities of southern Turkey, with relative frequency, are found specimens with a uniform purplish brown or black color ((severum Chaudoir, rapax Motschoulsky), similar to the rare individual forms that occasionally have been encountered in various localities of central Europe and that were differently named (habelmanni Schilsky, corvinum Heller, lapougei Breuning).

Notes: Winged diurnal but in some case can be attracted to light at night. It is inhabitant of both coniferous and decidous forests. Adults and larvae are excellent climbers and feed on Lymantridae and Thaumatopoeidae (Thaumatopoea pityocampa Denis & Schiffermuller, Lophirus pini Linné, Thaumetopoea processionea Linné, Lymantria dispar L., Euproctis chrysorrhoea Linné) and other caterpillars infesting trees of genera Pinus, Quercus and Fagus. Adults hunt trunks and treetops during the day and go down to the ground at around sunset and then hide in leaf litter at the foot of the trees.
Captures of active individuals have been noted from April to August and they are quite long lived as they seem able to survive up to 4 years (Dowden, 1962: 51). It is not rare to find specimens overwintering in small cavities in the ground. Calosoma sycophanta is an handsome beetle that has attracted, since the first steps of entomology, the interest of entomologists. It is one of the few Carabidae represented in the volume of Aldovrandi (De Animalibus Insectis Libri septem cum singulorum Iconibus ad vivum expressis 1638: 450, fig. 6) under the name of Scarabaeus viridis. Later Reamour (Memoires pour servir a l'histoire des Insectes, vol. II, 1736: 455 and plate 37 fig. 18) has given an account of its way of life. Subsequently there have been numerous illustrations in books of this beautiful species. It can still be interesting to recall that, because of its rarity in the British Isles, Donovan (The Natural History Of British Insects, vol. XIV, 1810: pl.477) has drawn in its place the Calosoma (Calodrepa) scrutator. This error has been then corrected by Curtis (British Entomology, 1823-1840: pl.330).
The larva of C. sycophanta has been repeatedly described and drawn, starting with the first news given by Reamour (1736, vol. II: plate 37 fig. 14, 17).